Computing machine



E. THOMAS.

} COMPUTING MACHINE.

APPLICATION FILED DEC. 1, 1919.

1,413,999. ed p .25,1922.

UNITED STATES PATENT OFFICE.

EDWARD THOMAS, OF NEW YORK, N. 'Y.,

ASSIGNOR TO UNDERWOOD COMPUTING MACHINE COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

OOMIPUTING MACHINE.

Specification of Letters Patent.

Patented Apr. 25, 1922'.

Application filed December 1, 1919. Serial No. 341,749.

T 0 all whom it may concern:

Be it known that I, EDWARD THOMAS, a citizen of the United States, residing in New York city, in the county of New York and State of New York, have invented certain new and usefulImprovements in Computing Machines, of whichthe following is-a specification.

This invention relates to computing machines, and is herein'described as applied to an Underwood standard bookkeeping machine many of the features of which are disclosed in the patent to Ogden Minton, No. 1,280,065, dated September 24, 1918.

In computing machines which subtract, the handling of negative numbers is often a difficultproposition, both mechanically and functionally, since the digits ordinarily used for reading positive numbersdo not display the correct. negative number when their wheels are rotated backwardly or operated in anyway to effect subtraction, but instead display its complement less one. This one is known as a fugitive unit, and many kinds of devices, for the most part extremely complex, have been devised for use in computing machines to care for this fugitive unit. Such devices usually involve some modification of the carry-over mechanism, or of the adding-wheel-driving mechanism, or both, and not only add materially to the expense of building the mechanism, but also add seriouslyto its complexity and consequent liability to become deranged.

According to the present invention, practically all of these complexities may be avoided by employing a shutter, and an automatic control for the shutter, so that the shutter may be set to display the correct di its.

' he present invention is herein disclosed as an improvement on the co-pending application of Louis E. Giles, Serial No. 321,616, filed September 4, 1919, (now Patent No. 1370, 126, dated March 1, 1921,) wherein |is shown an ordinaryUnderwood-Hanson or Underwood standard bookkeeping machine,-

having an additional set of dial numerals, especially arranged upon the dial wheels, and a shutter which normally displays one set of digits, but which is adapted to be positioned by the typist to display other numerals, which, in the case of negative numbers, may be the numerals forming the true answer. According to the form of the present invention illustrated herein, the shutter, shown in said application, may be shifted, as shown and described therein, and there may be provided devices for automatically arresting the shutter when it arrives a the proper position. v The mechanism ma also include means for holding the shutter thus positioned until the typist has copied off the number displayed thereby, and means for automatically releasing it. One convenient form for eifectingsuch result is in connection with the actuation of the general operator, which automatically takes place upon writing the units digit of the form of the Underwood-Hanson machine, shown in vantageous to utilize the ordinary detents, which control the star-printing key; these detents being somewhat modified for the purpose.

Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is afragmentary plan view of an Underwood standard bookkeeping machine of the kind referred to, many details being omitted.

Figure 2 is a sectional side view, showing many of the parts shown in Figure 1, and also showing part of the driving mechanism for the numeral wheels.

Figure 3 is a plan view of part of Figure 1, but showing the. shutter set to disclose the negative number 9,898,000. I

Figure t is a fragmentary side view of a numeral wheel at 0, together with its detent and a few co-operating parts.

In an Underwood-Hanson combined typewriting and computing machine, numeral keys (not shown) actuate the types (not shown), to print upon the platen (not shown).

Each. numeral key, when actuated in a computing zone, carries down its pin-setting bar 10 to set a corresponding pin 11 upon a pin-bar 12, which, at the moment, is shifted from its Figure 2 position to the usual computing position, the structure being more fully set forth in said Minton patent, and in various other patents. When a number has been completely written by the numeral keys and set up by depressing the appropriate pins 11, it is carried into the numeral wheels 13 by actuating a general operator 14, which is drawn forward, as shown diagrammatically herein, by drawing forward a handle 15, so that a cross-bar 16, forming part of the operator, engages the pin-bars 12 by their depressed pins and turns the numeral wheels 13 corresponding extents by means of racks 17 on the front ends of said pin-bars, said racks meshing with pinion's ;18, having'a one-way connection with the numeral wheels 13. Usually in these machines, the general operator 1 1 is actuated by an electrical motor, which is automatically started at the end of each computing zone. The. motor, however, is not shown in the drawings to avoid complexity. ()n the return stroke of the general operator 14, a carry-over drive-shaft 19 is rotated to drive any numeral wheels 13 whose carryover wheels 20 may have been set upon the forward movements of the general operator. The drive-shaft 19 is driven in the usual manner by the Iusual one-way clutch and pinion 21, which meshes with a rack-bar 22, forming part of the general operator.

To effect subtraction, a subtraction-key 23, of any ordinary or desired form, may be actuated before writing the digits of the number, and this subtraction-key in the Underwood-Hanson machine sets mechanism for effecting complementary, subtraction. This mechanism includes a 9 pin-setting bar 24 to set the 9 pins, and alters the connections from the numeral keys to the pin-setting bars 10, and also establishes a connection from the numeral keys to a 9 pin-restoring bar 25. I V

In finishing computing operations on these machines in positive ,numbers, it is usual to subtract out the total shown upon the numeral wheels 13 by printing the total as the final entry of the computation, and then to prove the correctness of the work by actuating a star-printing key 26, which is normally inoperable but which becomes operable when all the numeral wheels 13 stand at O. The connections for doing this are shown in some detail in the patent to Richard F. Hoyt, No;1,256,309, dated February 12, 1918. As herein illustrated, the starprinting key-26 comprises a lug 27 which normally overlies a bail 28, journaled by arms 29 upon a shaft or on pivots 30. The bail 28 is pressed inwardly'toward the wheels 13 by a spring-31, but is normally held in the Figure 2 position under the lug 27, because one or more of the detents 32 (of which there is one for each numeral wheel 13) are pressed outwardly by the teeth 33 on their respective wheels 13. /Vhen any wheel stands at 0, its detent 32 can seat itself in hollows 34, cut on the facing surfaces of the teeth 33, which are then adjacent the detent 32. When all the hollows are in the position shown in lligure l forthe nearest wheel 13, the spring 31 carries the bail 28 toward the wheels 13, clear of the lug 27. This, therefore, then-enables the free actuation of the star-printing key 26.

lVhenever the numbers subtracted upon the wheels 13 exceed the numbers added, the positive digit 9 upon the left-hand numeral wheel 13 appears at the usual sightopening along the lower edge of an opening 35 of the shutter 36. For reasons well known to those skilled in the art, this 9 is an indication that the numerals are to be reckoned as displaying a negative number,- and not the true negative number itself, but its complement, save for the error of the fugitive unit. To enable the typist to read directly from the numeral wheels 13 the true negative number represented by the complement shown, the shutter 36 is adapted to be shifted to the right by a handle 37, the shutter sliding on a suitable way 38, with the result that the positive digits previously at the lower edge of the opening 35, so far as they are significant, are concealed by a stretch 38 of the shutter to the left of the handle 37.

To enable the true number to be read, the numeral wheels 13, in addition to the digits shown adjacent the lower edge of the opening 35 in Figure 1, comprise negative readin digits (usually red) shown in broken lines at an opening 39, in Figure 3. Said digits are adapted to be read in part through said opening, and give the true reading and, therefore, are called negative digits. The positive and negative digits are arranged relatively to each other in the manner shown and described in said above-mentioned application, Serial No. 321,616, with the result that each positive digit, when added to the adjacent negative digit on one side, will total nine, and, when added to the adjacent negative digit on the other side, will total ten.

The shutter 36 is normally drawll to the extreme. left by a spring 40 to the Figure 1 position, in which it is held arrested by its handle 37, which, in this position, lies against an edge 41 of the casing 42 of the machine. To read the correct negative number, the shutter is pulled to the right by its handle 37 until its handle conceals the extreme right-hand positive significant numeral, at

which position, according to the present invention, the shutter is automatically arrested, as will presently appear. In this position, which is the Figure 3 position, the wheel 13, displaying the broken negative digit or numeral 8 at the handle 37, has the corresponding positive digit or numeral 2 concealed at the handle 37. The negative numher to be read is partly through the opening 39, the upper edge of which is substantially in alignment with the lower edge of the opening 35, and partly at the upper edge 43 or the opening 35 beginning at a notch 48, and reads 009,898,000. l Vhen the shutter is set at any position, such as the Figure 3 position, it. is detained there by a pawl 44, which is normally drawn by a spring to engage a rack 46, having teeth spaced to hold the shutter with its handle 37 intermediate any of the numeral wheels 13. This leaves both hands of the typist free to write, by the usual numeral keys, the negative numerals shown. An auxiliary shutter, which may be used to norm-ally conceal the negative numerals along the edge 43, and which may be automatically shifted to ineffective position at any movement of the handle 37 -to the right, is omitted for simplicity in the showing.-

The shutter 36 may sometimes be drawn far enough to the right to carry the handle 37 into a notch 47 in the casing 42, in which .position all of the positive numerals are concealed. In this position of the shutter 36, all the negative numerals, except the ex-. treme right-hand one, are read through the opening 39, the right-hand one being read at the edge 43. In other positions of the shutter 36, a less numberof wheels 13 show their negative numerals through the opening 39,

so the negative numerals are to be read through the opening 39 as far as possible beginningv at the left, and the remainder along the edge 43.

To release the shutter when the typist has copied the numbers, the carry-over drive shaft 19 may be utilized. since it always actuates when computing the written digits. There is provided on said shaft a cam 49 in which is a hollow 50 adapted to normally accommodate a toe 51 on an extension 52 of a pawl-releasing arm 53, which is journaled on a shaft 54 which carries the carry-over wheels. what enlarged opening 55 in the pawl 44, with the result that whenever the carry-over drive-shaft is actuated, the toe 51 rides out of the hollow 50 onto a long dwell 56, of the cam 49, thus withdrawing the pawl 44 and holding it withdrawn until the drive-shaft 19 has substantially completed its operation. This finally brings the hollow-50 to the toe 51, allowing the spring 45 to make the pawl again effective.

To automatically arrest-the shutter 36 at the correct position. when it is drawn to the right by the handle 37,-the shutter is provided with a lug 57', which lies clear of the usual positions of arresting lugs 58, forming the upper extensions of the detents 32. \Vhenever any detent 32 stands in the Figure 4 position, its arrestinglug 58 stands in the path'of the shutter lag 57, and prevents the shutter from traveling farther. Thus, any feeler or detent 32, co-operating with its wheel at the 0? position, serves to arrest the shutter. To prevent the arresting of the shutter by a detent 32 in its 0 position. if

there is a numeral wheel to the right thereof The arm 53 extends into a someshowing a significant digit, each detent 32 is shown herein as having a lug 59, which overlies the adjacent lug or detent to the right, with the. result that if any detent 32 is held outwardly because its numeral wheel stands in a non-zero position, its detent 32 will hold outwardly all of the detents 32 to its left, even though some of their wheels may stand at 0. This insures that the shutter, on being pulled to the right, is arrested with its handle 37 covering the righthand significant positive numeral.

It will be observed that the bail 28 or an equivalent part may be entirely independent of the star-key 26. It is, however, shown herein in such relation thereto to illustrate how the mechanism may be inserted in an ordinary standard machine.

In order to hold any detent or feeler 32 in its Figure 4 position when its wheel reaches its Figure 4 position, it is provided with a suitable individual spring 60. To hold the detents- 32 against endwise displacement when the shutter strikes them, there is provided a comb 61, suitably supported in the frame '42. To support the rear end of the shutter 36, there may be provided headed screws or rivets 62, whichrun in a slot 63 in the shutter. In Figure 3, the right-hand feeler or detent 32 is shown as provided with the lug 59, which, however, is shown in said figure merely for the sake of deafness, and need not in practice appear.

Variations may be resorted to within the scope-of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I .claim:

1. In a computing machine, the combinationwith dial wheels having numerals for positive numbers and numerals for negative numbers, of a shiftable shutter adapted tonormally conceal negative numerals, and mechanical means for variably arresting the shutter to display the correct numerals when shifted todisplay the negative numerals.

2. In a computing machine, the combination with dialwheels having numerals for positive numbers and numerals for negative numbers, of a manually shift-able shutter adapted to be variously ositioned to conceal some numerals and isplay others, and mechanical means for variably arresting the shutter at a .point where it will display only correct negative numerals when negative numbers are to be read. a

'3. In a computing machine, the combination with dial wheels having numerals for positive numbers and numerals for negative numbers. of a shutter, a feeler for each denomination adapted to be selectively positionedby the adjacent wheel, and a shutterarresting lug co-operating with an effective feeler to arrest the shutter.

4.. In a computing machine, the oombina- 13 tion with an array of dial wheels each having two sets of numerals thereon, one for positive numbers and one for negative numbers, of' a detent for each wheel, a shutter shiftable to selectively cover and uncover said numerals, and means whereby any detent may be positioned by its wheel to arrest the shutter.

5. In a computing machine, the combinas tion with a casing having an opening and an array of numeral wheels readable through the opening, of' a shutter slid'ahle across said. opening and normally concealing certain of the numerals, but comprising an opening adapted to make them visible and conceal other numerals, a detent for each wheel adapted to be selectively positioned to arrest the shutter or let it pass, and means for detaining the shutter wherever it is positioned. I

6. In a computing, machine, the combination with a casing having an opening and an array of numeral wheels readable through the'opening, of computing mechanism for driving said' wheels, a shutter slidable across said opening and normally concealing-certain of the numerals}, but comprising an opening adapted to make them visible and conceal the other numerals, means controlled by the wheels for selectively arresting the shutter to selectively cover and uncover numerals, means for holding the shutter wherever it is positioned, and means automatically effective at the conclusion of an operation of the computing mechanism for releasing the shutter to return it to normal position.

I In a computing machine, the combination with a casing haying an opening and an array of numeral wheels readable through the opening, of computing mechanism for driving said wheels, a shutter slidable across said opening and normally concealing certain of the numerals, but comprising an opening adapted to make them visible and conceal the other numerals, a key adapted to be used for clearance printing, detents controlled by the wheels for controlling said key,-and means whereby said detents control the shutter for selectively arresting it to selectively cover and uncover numerals.

8. In a combined typewriting and computing machine, the combination with a key adapted to effect clearance printing, of detents, numeral-wheels adapted to variously position said detents, means whereby in one position the detents bloc-k said key, and a shutter also controlled by said detents.

9. In a combined typewriting and computing machine, the combination with a key adapted to eflect clearance printing, of detents, numeral Wheels adapted to variously position said detents, means whereby in one position the detents block said key, and a shutter also controlled by said detents, said Wheels comprising positive and negative digits, adapted to be selectively and variably covered and uncovered by said shutter.

10. In a computing machine, the combination with numeral ,wheels, of a shutter adapted to be slid to selectively cover and uncover numerals on said wheels, a f'eeler bearing radially upon each :wheel, means whereby any feeler may become effective to arrest the shutter, and means whereby any f'eeler may be effective 011 any feeler to one side of it while ineffective on the other feelers.

11. In a computing machine, the combination with numeral wheels, of' a shutter adapted to he slid to selectively cover and uncover numerals on said wheels, a pivoted feeler bearing radially upon each wheel, a lug on each feeler save one and overlapping the adjacent feeler onone side, so that one end feeler controls all the feelers to the other end, and means whereby any feeler may become effective to arrest the shutter and make an adjacent feeler effective by its lug.

12. In a computing machine, the combination with numeral wheels, of a shutter adapted to he slid to selectively cover and uncover numerals on said wheels, teeth on said wheels, detents adapted to seat themselves between said teeth, certain of said teeth being cut out to enable a detent to seat itself more deeply therein, means whereby any detent holds out any detent to its left, and means whereby any detent arrests the shutter when slid from the left.

13. In a computing machine, the combination with numeral wheels, of a shutter adaptedto be slid to selectively cover and uncover numerals on said wheels, a ivoted feeler bearing radially on each W eel, a lug on each feeler save one and overlapping the adjacent feeler on one side, so that one end f'eeler controls'all the feelers to the other end, means whereby any feeler may b come effective to arrest the shutter and make an adj aeent teeler effective by its lug, means for detaining the shutter when so slid, computing mechanism for driving the wheels, and connections for automatically releasing the shutter and returning it to normal position at the end of an operation of the mechanism.

14. In a computing machine, the combination with a casing, of computing Wheels having numerals visible through an opening of said casing, said numerals comprising positive numerals and negative numerals so arranged that a positive numeral foots to ten with one adjacent numeral and to nine with the other adjacent numeral, a shutter normally exposing the positive numerals, means for shifting the shutter to expose some of the negative numerals, and means associated with each numeral wheel adapted to be variably positioned thereby to be effective to arrest the shutter according to the position of its numeral Wheel.

15. In a computing machine, the combiciated with each numeral wheel adapted to be' variably positioned thereby to be effective to arrestthe shutter according to the position of its numeral wheel, computing mechanism for driving said wheels, and means controlled by the actuation of said mechanism to return said shutter from its shifted position to a normal, positive reading position.

16. In a computing machine, the combination with a casing, of computing wheels having numerals visible through an opening of said casing, said numerals comprising positive numerals and negative numerals so arranged that a positive numeral foots to ten with one adjacent numeral and to nine with the other adjacent numeral, a. shutter normally exposing the positive numerals, means for shifting the shutter to expose some of thenegative numerals, means a ociated with eachnumeral wheel adapted ha be variably positioned thereby to be efiective to arrest the shutter according to the position ofits numeral wheel, a device for detaining the shutter in its shifted position, a spring normally tending to return it, computing mechanism for driving said wheels, and means actuated by said mechanism for automatically making the detaining device efli'ective.

17. In a computing machine, the combination with a casing, of computing wheels having numerals visible through an opening of said casing, said numerals comprising positive numerals and negative numerals so arranged that a positive numeral foots to ten with one adjacent numeral and to nine with the other adj acentnumeral, a shutter normally exposing therpositive numerals, means for shifting the shutter to expose some of the negative numerals, means associated with each numeral wheel adapted to be variably positioned thereby to be effective to arrest the shutter according to the position of its numeral wheel, computing mechanism comprising devices on which, numerals are temporarily set up, means for carrying the setup numerals into the wheels, means for detaining the shutter in its shifted position, and means made effective by the carrying-in means for returning the shutter to normal position.

18. In a computing machine,'the combination with a casing, of computing wheels having numerals visible through an opening of said casing, said numerals comprising positive numerals and negative numerals so arranged that a positive numeral foots to ten with one adjacent numeral and to nine with the other adjacent numeral, a shutter normally exposing the positive numerals, means for shifting the shutter to expose some of the negative numerals, means associated with each numeral wheel adapted to be variably positioned thereby to be effective to arrest the shutter according to the position of its numeral wheel, computing mechanism comprising devices on which numerals are temporarily set up, means for carrying the setup numerals into the wheels, means for detaining the shutter in its shifted position, a carry-over drive-shaft-adapted to carry-over on said wheels, and means controlled by said drive-shaft for returning the shutter to normal position.

19. In a computing machine, the combination with numeral-wheels having positive and negative digits thereon, of a feeler bearing upon each wheel, each of said wheels being so formed that the corresponding feeler will be in one position for a zero setting of 'said wheel and in another position for. any other setting of the wheel, means whereby any one of said feelers when moved out of the'position for a zero setting of the corresponding numeral-wheel will hold the feelers at the left thereof in corresponding positions, and means for reading negative results controllable by said feelers.

20. In a computing machine, the com ination with dial-wheels having digits for positive numbers and digits for negative numbers, of a shiftable shutter adapted, when in normal position, to direct attention to positive digits, and means controllable by said wheels for variably arresting the shutter to direct attention to the correct negative digits when shifted to positions to read negative results.

EDWARD THOMAS. Witnesses:

LEWIS E. WEBER, EDITH B. LIBBEY. 

